The present invention pertains to content control systems and more particularly to a method and apparatus for detecting modifications purposely made to prior art signals such as for example, copy information signals or copy protection signals such as sync signal or color burst modifications, or pseudo sync or automatic gain control (AGC) signals in any combination, to form a subsequent content control command for controlling a compliant device. Ergo, a modification to a conventional signal, arrangement of signals or the number of signals detected determines the operation of the compliant device.
For example, if a pseudo sync or AGC signal is detected, the resulting content control command provides a predetermined control to a compliant device. If one signal is detected, the compliant device may record or display for an hour. If two signals are detected the compliant device may shut down or display an error signal in response to the content control command.
Such compliant device includes a reader, sensor or detector of one or more copy information signals such as a CGMS or data signal, and or to a copy protection signal such as an AGC and or pseudo sync signal.